Theorem r19.43 2512

Description: Restricted version of Theorem 19.43 of [Margaris] p. 90. (Contributed by NM, 27-May-1998.) (Proof rewritten by Jim Kingdon, 5-Jun-2018.)

Assertion

Ref	Expression
r19.43	|- ( E. x e. A ( ph \/ ps ) <-> ( E. x e. A ph \/ E. x e. A ps ) )

Proof of Theorem r19.43

Step	Hyp	Ref	Expression
1		df-rex 2354	. . . 4 |- ( E. x e. A ( ph \/ ps ) <-> E. x ( x e. A /\ ( ph \/ ps ) ) )
2		andi 764	. . . . 5 |- ( ( x e. A /\ ( ph \/ ps ) ) <-> ( ( x e. A /\ ph ) \/ ( x e. A /\ ps ) ) )
3	2	exbii 1536	. . . 4 |- ( E. x ( x e. A /\ ( ph \/ ps ) ) <-> E. x ( ( x e. A /\ ph ) \/ ( x e. A /\ ps ) ) )
4	1, 3	bitri 182	. . 3 |- ( E. x e. A ( ph \/ ps ) <-> E. x ( ( x e. A /\ ph ) \/ ( x e. A /\ ps ) ) )
5		19.43 1559	. . 3 |- ( E. x ( ( x e. A /\ ph ) \/ ( x e. A /\ ps ) ) <-> ( E. x ( x e. A /\ ph ) \/ E. x ( x e. A /\ ps ) ) )
6	4, 5	bitri 182	. 2 |- ( E. x e. A ( ph \/ ps ) <-> ( E. x ( x e. A /\ ph ) \/ E. x ( x e. A /\ ps ) ) )
7		df-rex 2354	. . 3 |- ( E. x e. A ph <-> E. x ( x e. A /\ ph ) )
8		df-rex 2354	. . 3 |- ( E. x e. A ps <-> E. x ( x e. A /\ ps ) )
9	7, 8	orbi12i 713	. 2 |- ( ( E. x e. A ph \/ E. x e. A ps ) <-> ( E. x ( x e. A /\ ph ) \/ E. x ( x e. A /\ ps ) ) )
10	6, 9	bitr4i 185	1 |- ( E. x e. A ( ph \/ ps ) <-> ( E. x e. A ph \/ E. x e. A ps ) )

Syntax hints:   /\ wa 102   <-> wb 103   \/ wo 661   E.wex 1421   e. wcel 1433   E.wrex 2349

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-io 662  ax-5 1376  ax-gen 1378  ax-ie1 1422  ax-ie2 1423  ax-4 1440  ax-ial 1467

This theorem depends on definitions:  df-bi 115  df-rex 2354

This theorem is referenced by:  r19.44av  2513  r19.45av  2514  r19.45mv  3335  iunun  3755  ltexprlemloc  6797